Thunderstorm asthma inquest to probe deadly weather event

Asthma sufferers may have been safest staying indoors with windows closed and medication on hand when a fatal thunderstorm respiratory event struck Victoria, an inquest has been told.

A specialist today gave evidence to an investigation into the deaths of 10 people, during or shortly after the freak weather event hit Melbourne in November 21, 2016.

Professor Jo Douglass arriving at the inquest today. (AAP) (AAP)

The event, caused by a combination of high pollen, strong winds, high temperatures and air moisture before a cold front, sparked an unprecedented surge of emergency calls across Victoria.

About 14,000 people were taken to hospital and seven men and three women - aged 18 to 57 - died.

Professor Jo Douglass, from Royal Melbourne Hospital, said there was a trend of the victims having spent time outdoors before their deaths, which occurred on a hot 38C day with lots of pollen in the air, ahead of a storm.

Law student Hope Marsh, 20, had felt wheezy and was taken outside to get some "fresh air" before she collapsed and died outside her home, the coroner heard.

Hope Carnevali died during the thunderstorm asthma event last year. (60 Minutes) ()

Clarence Lea, 37, had the door open and was out of asthma medication when he became distressed, collapsed and suffered fatal respiratory failure.